Email Users in UAM group

I am going to write a plugin that emails users when a post is published. The plugin will check the post for the uam groups it is apart of and then use that result to find all users apart of those groups. Once an array of the valid users is created email notifications will be sent to all of them.

I was hoping I could get some help as to how I can start. I would like to save myself a few hours of debugging through the uam functions to figure out exactly how they work. Could you point me in the right direction?

On another note I believe a way to backup the changes uam has made to the database a necessary feature. My problem is that I had to modify one of the uam files so that the access box would appear on my custom post types. I believe if I were to update the plugin everything would be lost including all groups and group assignments. Is there a work around for this issue?

http://wordpress.org/plugins/user-access-manager/